Function Of The Tubules Flashcards
Lining of PCT
What function does it serve
Simple cuboidal brush border epithelium
Incresse surface area for absorption
What does PCT reabsorb
Nearly all of the essential nutrients
70-80% of electrolytes and water
Benefits of reabsorption by PCT
Maintain pH and ionic balance of the body fluids by selective selection of H ions, NH3, and K ions into the filtrate and absorption of HCO3- from it
Which limb of Henle’s loop has minimum reabsorption?
The limb plays a significant role in what?
Ascending
Maintenance of high osmolarity of medullary interstitial fluid.
Permeability of descending loop of Henle?
What does this aid?
Permeable to water but almost impermeable to electrolytes
This concentrates the filtrate as it moves down
Permeability of ascending limb of Henle?
What does this cause?
The ascending limb is impermeable to water but allows transport of electrolytes actively or passively.
Therefore, as the concentrated filtrate passes upward, it gets diluted due to the passage of electrolytes to the medullary fluid.
What substances does DCT reabsorb?
- conditional reabsorption of Na+
and water
2.reabsorption of HCO3–
3.selective secretion of H, K ions and NH3 to maintain the pH and sodium-potassium balance in blood
Collecting duct location
Long duct extends from the cortex of the kidney to the inner parts of the media
What does collecting duct absorb? Why?
Large amounts of water
To produce a concentrated urine
Collecting duct functions
- Large amounts of water could be reabsorbed from this region to produce a concentrated urine.
- This segment allows passage of small amounts of urea into the medullary interstitium to keep up the osmolarity.
- It also plays a role in the maintenance of pH and ionic balance of blood by the selective secretion of H+ and K+ ions
